The present invention relates to a fifth (little) toe support primarily within sport shoes such as running or jogging but also applicable to walking shoes. The support is made of essentially flexible and resilient material that is placed only under the proximal portion of the fifth proximal phalanx or it may be an extension of a semi-rigid foot support extending from the heel to the forward edge of the metatarsal bones. In either case, this fifth ray extension terminates distally underneath the neck portion of the fifth proximal phalanx to improve stability and forward balance.
Running and jogging present different and more critical problems in foot biomechanics than does the normal walking operation. In the running gait with contact, midstance, propulsion and swing phase, there is a shifting of varying degrees, the torque peaks at the end of midstance and the supernation and pronation forces on the foot are greater. Thus the maximum forces occur in the forefoot area.
A runner with the greatest continuity of motion will be one with a normal foot that produces linear shear forces against the foot during contact and again during propulsion. Lateral sheer forces--side to side--motion of the trunk are generally not as significant during normal walking locomotion. However in running and jogging they may have a greater effect, and may be accentuated by any of several pathological conditions which exaggerate lateral motion such as lateral imbalance.
When a person runs, in each stride the ball of the foot, and particularly the portion of the ball of the foot at the little toe, of the forward foot touches the ground first, then the foot rolls forward shifting weight forward onto the toes which bend and unbend as the person's body moves forward over and beyond the toes. This bending and unbending of the toes produces a springy forward functional thrust to the forward motion of the running body. As the person's weight moves forward from the ball of the foot onto the toes, the foot rotates slightly inward due to the staggered arrangement of the toes and the contour of the ball of the foot. This inward rotation is a natural part of the foot movement which enables each toe in succession, beginning with the little toe, to contribute its own component of springy forward thrust. However, if the foot is laterally imbalanced, or if the metatarsal bone which precedes the little toe is unnaturally short, there will be insufficient inward rotation for the most efficient forward thrust, or worse, there will be outward rotation which tends to throw the body off balance, impeding efficient motion or perhaps even causing a sprain or a pulled muscle.